The present invention relates to a heating or air-conditioning unit for a motor vehicle, which can be used to supply individual air-conditioning zones of the vehicle passenger compartment with air that can be temperature-controlled separately.
FR 2717747 discloses an air-conditioning system which can be used to separately set the temperature of the air supplied to the different air-conditioning zones, namely xe2x80x9cat the front on the rightxe2x80x9d (front passenger""s seat) and xe2x80x9cat the front on the leftxe2x80x9d (driver""s seat) and also for a xe2x80x9crear compartment on the leftxe2x80x9d and for a xe2x80x9crear compartment on the rightxe2x80x9d. For this purpose, the air-conditioning system has two air-conditioning units for respectively supplying the left or right half of the vehicle. The front region and the rear region can be supplied with air controlled to different temperatures by each of the air-conditioning units. This air-conditioning system is very complicated, since it has two air-conditioning units, each having a fan, evaporator and heating unit along with corresponding air ducts. The system is therefore correspondingly expensive and can only be used in large-capacity vehicles because it requires a large amount of space.
DE-A 197 39 578 discloses an air-conditioning unit with air-side control (air-blending), in which the space downstream of a heating unit is divided into four air-mixing spaces which lie next to one another and are separated by partitions. In these air-mixing spaces, cold air guided below the heating unit is mixed with hot air. The partitions extend below the heating unit and divide the cold-air bypass into four subducts as well. An individual temperature can be set in each mixing space independently of the temperatures in the other mixing spaces, via hot-air flaps arranged directly downstream of the heating unit and cold-air flaps that selectively close the cold-air bypasses. The air from the individual air-mixing spaces which has been temperature-controlled individually can be supplied via air ducts to the corresponding air-conditioning zones.
The general problem underlying current ventilation, heating or air-conditioning units together with their components, in particular the air flaps, is that the structural space which is available for the air-conditioning unit is very restricted, and these units therefore have to be constructed ever more compactly. In particular, air-conditioning units that are suitable for controlling different air-conditioning zones to different temperatures require a relatively large structural space because of their relatively large number of components.
Therefore, one object of the invention is to provide an improved heating or air-conditioning unit with which air which can in each case be temperature-controlled individually for the different air-conditioning zones of the vehicle, and which requires the smallest possible structural space.
In accomplishing one or more objects of the invention, there has been provided according to one aspect of the invention a heating or air-conditioning unit for a motor vehicle, comprising: a heating unit for generating heated air; a plurality of cold-air ducts bypassing the heating unit; a plurality of air-mixing spaces that are located downstream of the heating unit in the direction of air flow and that are separated from one another by at least one partition, each of the air-mixing spaces being in fluid communication with one of the cold air ducts and with the heating unit; air-flow control elements arranged so that cold and heated air can be introduced in a controllable manner into each mixing space in order to mix the air to a predetermined mixing temperature; and
at least one conditioned-air duct communicating with each air-mixing space for supplying air which has been temperature-controlled separately to at least two air-conditioning zones in the vehicle, wherein the cold-air duct and the air-flow control elements are arranged to provide that at least one first partial air stream to be heated in the heating unit flows through a first assigned subregion of the heating unit in a first direction, and at least one second partial air stream to be heated in the heating unit flows through a second assigned subregion of the heating unit in a second direction opposed to the first direction.
Further objects, features and advantages of the invention will become apparent from the detailed description of preferred embodiments that follows, when considered together with the attached figures of drawing.